Hoisting



June l 1926.

R. J. WADD ET AL HOISTING Filed May 14, 1924 Patented June 1, 192.

1,587,259 UNITED srares PATENT oFFICE.

ROY J. WADD, 0F MONTOUR FALLS, NEVI YORK, AND EDWARD G. PAB/VIN, OF ROSELLE,

NEW JERSEY, ASSGNORS TO SHEPAED ELECTREC CRANE t HOIST COMPANY, 0 MONTOUR FALLS, NEW YORK, A CGREORATON GF NEW YORK. Y

HOISTING.

Application filed May 14, 1924. Serial No. 713,164.

ln a known method of manufacturing ice now coming into use, cakes ory bloc-lis of ice are formed by the congelation of water in cans dipping into a brine bath suitably cooled to freeze the water, and after the ice cakes are formed the brine is heated up suiiiciently to thaw the ice blocks loose from cans whereupon the ice blocks are removed from the cans which remain permanently in the brine tank instead of being removed from the latter to permit the discharge of the ice as has heretofore been the usual practice. The period of time required for thawing an ice cake loose from the `walls of the can in which it is formed, varies with conditions and not infrequently amounts to a half hour or so. Each ice cake thus formed ordinarily weighs several hundred pounds and its removal is best effected by means of an overhead hoist mounted on a traveling crane, the hoist ordinarily being attached to the ice cake by connecting the hoist hook to an eyebolt frozen into the ice cake.

The object of the present invention is to provide an improved method of removing ice cakes from the stationary cans in which they are formed. To remove an ice caire in accordance with the present invention, we employ a hoistdriven by a suitable and suitably energized electric motor and attach the hoist hook to an ice cake, or to a plurality of ice cal-:es which are to be simultaneously removed, at any convenient time after the ice cake or cakes are formed and before they are thawed loose from the cans in which they are formed, and then energize the motor and maintain its energization until the ice calze or cakes thaw loose, whcreupon the hoist lifts the cake or cakes out of the cans. For the purposes of our invention, the hoist motor employed must be of such character and be connected into such an energizing circuit that when the motor is energized, its torque will be ample to lift the weight of the calie or cakes of ice which it is to draw out of the cans, and will not be great enough to subject the cans or ice cakes to undue strain while the ice calles are still frozen to the walls of the cans, aud the motor itself will not be overheat-ed or otherwise injured by the maintenance of its enerthawed loose from the cans. No special or unusual form of electric motor is required for this purpose as some existing motors are well adapted for this service and require no, or a relatively small amount of external resistance to prevent an undesirably large current flow through the motor.

The various features of novelty whit-lr characterize our invention are pointed ont with particularity in the. claims annexed to and forming a part of this specification. For a better understanding of the invention, however, reference should be had to the accompanying drawings and descriptive mat-- ter in which we have illustrated and described suitable apparatus for carrying out our invention.

Of the drawings:

Fig. l is a somewhat diagrammatic view partly in section of an ice making plant;

Fig. 2 is an elevation taken at right angles to Fig. 2; and

Fig. S is a diagram illustrating characteristics of a suitable hoist motor.

in the drawings A represents the brine tank of an ice making plant with stationary cans B for the water to be frozen into ice cakes which dip into the brine space G in the tank A. Each ice cake D formed in a can E has incorporated in it a lifting element E shown as an eye-bolt, the head of which is above the top of the ice cake and the lower end of which may be enlarged as indicated in E to increase the strength of the connection between the eye-bolt and thev ice cake in which it is frozen. To remove an ice cake D from the can B in which it is formed, the corresponding` eye-bolt E is engaged by a hoisting` hook F. .As shown. the hoisting mechanism is intended to simultaneously lift two ice cakes D out of the cans in which they are formed, though it is to be understood that one, or more of two ice cakes may be removed from the cans at a single time. To provide for the simultaneous removal of two ice blocks D, the hoisting mechanism shown in the drawings is provided with two lifting hoolrs F connected by a bar G to the hoist pulley G. The latter is supported by the hoist rope or cable H which has one end connected to the hoisting drum H2 of an electric hoist H which comprises a suitable motor H3 for operating the drum H2. Aside from the requirement for a motor H3 having proper V--eliaracteristics forf-the present pur-- pose, the hoist H may be ot'fstai'idard eonstruction. As shown, the hoist H comprises supporting,` wheels H4 running` along the track rails'iL forming Aa part ot the train'i'e work-ofen overhead traveling craneL, the

wheels L2 of which run oirsupporting rails' The hoist-HL ions for interrupting` thehoisting inoveinent ofthe druinligfwhen' the 4pulleyiG-l reaches the desired upward liinit lot its travel.

the latter approaches the desired upper liinit et its n'ioveiiient, 'are well known and inA coin-- mon use no necessity is seen for'illustratiiig or describing` such provisions in detail herein.

the heist inotor Ht.

its inode of energization and energizing :circuit connections iiicluding'whatever externi-iil resistances may he necessary, shall have the fproper characteristics for theintended service.' Suitable vcharacteristics for a niotor for this service are indicated-in-Fig.-.

3 wherein@ Iis curve representing"l the strength or" theinotorenergizing current,'

andv a v`curve representing the inot-or torque ina diagrain wherein Athe ordinates represent both aniperes and torque foot pounds,` and Ithealo'scisse representinotor speed.V lVi'thl a inotor having the charactei' creases ine-re -or .less gradually as the niotor starts into operationand speeds up.

prevent it Yfrein hei-ng` :injured by overheat=- inn' ror otherwise lwhen continuously ener v:tl iorthe niaxiiniini period required for* thawingi `the' ice cake orice Acakes 'towhieh-iy the-"hoist is connected loose' 'trein-*the 'corresponding :cansfBE This period, fata ina`Xil iiiuin, will not'ordinsrily exceed ahalfhou-ror lso; The motor shouldheof Suchcharactor that th'ewinaiiinuin )lifting eifeet of the2A hoist will hesomewhat-inexcessA oit' the weightetV the ice cake or cakes to'be lifted out of the cans in one operation, andr will he sinailenough to prevent injury to tliefice Henergizediwhile the ice blocks are frozen to the cans..

arshould lie providedw As control provisions suitahle for this purpose ineludingan actu# ating partV G' engaged hy the pulley ,Gr when :thus avoiding'v all .thawing of the ice .then wfiriner t-lian the ice.

striicted, arranged 'and4 operated as here/ine y `S5 i tics illustrated in Fig'. 3, -itsy torquefis'" a inaXiiniini-attlie' tiine of starting and-dey The-- niotor should he-oa character which would he connected to the ice cake oreakes -to be removed from the cans and theehoist inotor energized at, 0r any convenient time after, the ice is formed, and the energiaati on 'of the inotor 1H* is then 'maintained nirtil the 'ice lol'ocks thaw loo'seroin' the'cans and.' lifted' above 'the"latte`r. Thense or the invention reduces thelahor cost of operation or" the ice plant as a whole, and reduces the care and attention which must he given to the operation of removing the ice trein the cans since, with the invention, 'the ice is reinoved troni the eens atiexact-ly the proper iiioinent` namely, the moment-at` which the blocks thaw loose from the cansfv tendency to. the. undue-` celes which results troni leaving the cakes D inthefcanswhilethe latter are -in contact with 'brine-which iis disclosed, inay je employedinliftinguan-y weight whi/ii it nil restrain in fierce has diinifn-I ished.

Apparatus conl-Lfrving.4 new descrii'iedv ourL inrentiong what 'we claini asnew and desireto secure hylietters Patent,l is

l. The method of removing lolocks off-ice troni stationary cans' in which'fthey` are ornied, `which .consists in' conneetingonefor f quired for the ice hloclrs'rto thaw loose from the cans, while Venergized to exert a hoist-= ing inechanisin operatedbyfaneleetriefnio,

lifting;`V vforce exceeding.. theY weightof theV tdt-ached hloch er blocks` of 'ice but Iinsuiii-` cient to impress an undue stress on the ice,`

and so energizing said Vinotor.I

2. The method of lii'tinga body'. initially suhgeeted to a restraining force subsequently 'diminishing:.which .consists in connecting the body while said force is'relatively largeI toa hoisting inech'einism operated rhyi'aiielectric-'motor adapted'to he held stationary without 'inpiry toitsel'f` throughout the pe riod required for said force to diminish',

while energized to exert av hoist lifting force' exceeding the weight ot sai-(tbody but less than Ithe -suinj-vot said weight and said rei` straining torce,Azk and -so-l energizii'iggf4 said i niocor.

Signed at 'Monteur Falls', in the-county of Schuyler and State `of New YorinA this ,1 10th day of May, A fDf. 1924.

blocks D orv the cans B, when the hoist is attached 'to the ice blocks and the motor nov ,il wenn May, ii. n. 1921i.

EDWARD e. rARvrN. 

